1. Field of the Invention
The present invention relates to a verification system for performing unidirectional or bidirectional verification between a master apparatus (main apparatus) and a slave apparatus (client apparatus).
2. Description of the Related Art
Several verification systems have been realized for performing to unidirectional or bidirectional verification between a master apparatus and a slave apparatus, such as printers and ink cartridges, portable game machines and game boxes, or batteries and battery-powered electronic equipment (handset phone, digital camera, digital video, notebook PC and so on), thereby preventing non-normalized products from being used improperly. Japanese Patent No. 2009-272299 can be considered an example of the prior art described above.
Nevertheless, in the previous verification systems, the non-volatile memory capable of storing verification key code in a non-volatile manner uses flash memory or EEPROM (Electrically Erasable and Programmable Read Only Memory), which can be manufactured without any special equipment or technology, and thus is cheap and easy to copy. Such problems usually appear in non-normalized products with duplicate chips. Furthermore, the verification algorithms used in the previous verification systems do not depend on the characteristics or abilities of the non-volatile memory (such as data writing speed); thus it is cheaper and easier to perform similar operations by using other components. Such problems usually appear in non-normalized products with compatible chips.
In view of the above problems, an object of the present invention is to provide a verification system capable of preventing non-normalized products with duplicate chips or compatible chips from being circulated.